The basis of affectively motivated helping of another in distress has long been debated by scholars in diverse disciplines. Work in rodents that took place more than 50 years ago suggested that rodents participate in affective communication. Now the author's laboratory has established an ethical and feasible test for rodent helping behavior that involves one rat freeing another from a plastic tube. The helping exhibited is consistent, reinforced, socially selective, and independent of immediate social contact. A recent modified version of the helping behavior test confirms that rats help a conspecific in need. In sum, the complex social behavior, expressed by rodents and primates including humans, validates the notion that mammals share a phylogenetic inheritance that promotes other-oriented affective behavior.